Bottle cap having liner retainer

ABSTRACT

A closure including a cap and a liner. The bottle cap includes a top, a skirt and a liner retaining protrusion. The top has a perimeter and an inside surface. The skirt depends downwardly from the perimeter. The liner retaining protrusion depends downwardly from the inside surface of the top and is adapted to prevent shifting of the liner with respect to the cap. the top, skirt and liner retaining protrusion may be monolithically formed. The liner retaining protrusion may be conical. The liner retaining protrusion may be spike-shaped. Alternatively, the liner retaining protrusion may include a cylindrical wall which depends downwardly from the inside surface of the top. The liner retaining protrusion may include an outwardly extending bead extending from a lower portion of the cylindrical wall. The liner retaining protrusion extends into the liner to retain the liner and prevent the liner from axially shifting with respect to the cap. The liner retaining protrusion may extend into and through the liner. Alternatively, the liner retaining protrusion may extend through the liner such that an intermediate portion extends axially through the liner and an end portion extends below the liner, the end portion extending at an angle with respect to the intermediate portion.

[0001] This application is a Continuation-in-Part of U.S. patentapplication Ser. No. 09/893,181 filed Jun. 26, 2001, entitled Bottle CapHaving Tear Tab and Sealing Bead, the entire contents of which isincorporated herein by this reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a new and improved bottle cap. Moreparticularly, the present invention is directed to a bottle cap havingan improved sealing bead configured to engage a container crown proximalthe maximum diameter thereof. The present invention is also directed toa bottle cap having an improved tear tab including a line of weaknessextending along a skirt upward from a bottom edge of the bottle cap andonto a top of the bottle cap. The present invention is also directed toa bottle cap having a liner retainer.

[0004] 2. Description of Related Art

[0005] An exemplar of a known cap for use with large water containers ofthe type used with water dispensers and water coolers is U.S. Pat. No.5,232,125 to Adams. The cap disclosed by the Adams '125 patent includesa top, a cylindrical side wall extending downward from the top, arounded corner interconnecting the top and the cylindrical side walls,and a tension ring configured to fit under the neck bead, that is acrown of a container neck. The cap disclosed by the Adams '125 patentalso includes internal upper and lower seal beads on the inside of thewall of the corner which are configured to tightly engage the containerlip and seal against leakage.

[0006] The large water containers used with such known caps aregenerally blow molded and include neck finishes that are trimmed orotherwise finished using conventional methods. Although the neckfinishes are somewhat standardized within the container industry, theactual heights of container neck crowns tend to vary to some degree dueto the trimming and other finishing processes. In the event thatexcessive material is removed from a container neck crown duringtrimming, the upper and lower seal beads of known caps of the typedisclosed by the Adams '125 patent might not effectively seal againstthe crown.

[0007] Caps of the type disclosed by the Adams '125 patent generallyinclude a score line having a curved portion which extends from the baseof the cap skirt to a horizontal portion. Although such score lines areeffective for removing the cap from a container, a substantiallyvertical score line is beneficial for manufacturing purposes becausecaps molded with vertical score lines are generally easier to uniformlyfill with molten resin and easier to remove from a mold. Due to thesubstantial skirt height of such caps, a single vertical score line ofthe type generally used on shorter caps, such as those disclosed by U.S.Pat. No. 6,082,567 to Bietzer et al., is generally insufficient toremove a cap from a large water container. Instead, a pair of verticaltear lines is needed to facilitate removal of the cap from a container.

[0008] An exemplar of a cap having a pair of vertical tear lines is U.S.Pat. No. 6,102,226 to Verderber which shows a bottle cap having a top, askirt, a tab, and vertical tear lines which extend from the tear tab andterminate on an upper portion of the skirt below the top. The Verderberpatent also discloses a bottle cap having a top, a skirt, a tab, and asingle vertical tear line which extends downward from acircumferentially extending, horizontal internal tear line. TheVerderber patent discloses yet another bottle cap including a top, askirt, a tab, and a single vertical tear line which extends around thetop at the intersection of a bevel and the top.

[0009] U.S. Pat. No. 6,177,041 to Bietzer shows another cap having atop, a skirt, a tear tab, and vertical tear lines which extend from thetear tab and terminate on an upper portion of the skirt. One of the tearlines disclosed by Bietzer extends close to the top while the other tearline terminates at a location somewhat below the top.

[0010] U.S. Pat. No. 5,909,827 to Bietzer et al. shows a cap having atop, a skirt, and vertical score lines which extend from the tear tab.One score line extends up to an upper slanted portion of the skirt. Theother score line extends from up the bottom of the skirt to the top.

[0011] Although conventional wisdom might imply that extending both tearlines to the top of a cap would be beneficial for removing the cap froma container, the prior art shows at least one tear line of a capgenerally terminating at a location somewhat below the top in order tofacilitate removal of the cap from the bottle. As described in theBietzer '041 patent, it was found that pulling on the tab of caps havinga pair of tear lines which extend to the top thereof actually caused alocking ring thereof to increase its grip on a bottle used therewiththus making the cap very hard to remove. In particular, pulling the tabof such caps causes a reduction in the effective diameter of the lockingring disadvantageously tightening the locking ring around the bottle.Thus, a user frequently needed to grip the skirt of such caps and prythem from the bottle.

[0012] Furthermore, removal of known caps generally does not completelyfracture and/or destroy all sealing means of the caps. Accordingly,users of known caps may be inclined to misuse the caps by reusing thecaps on a reusable bottle. Storage of potentially dangerous substancesis a major concern in the field of reusable bottles.

[0013] One aspect of many closures for bulk water containers is thatthey include a form of liner to increase the integrity of the seal. Onecommon form of liner comprises a plastic, highly compressible foam.Because they are highly compressible, these liners are able toaccommodate a wide range of bottle dimensions and common bottle finishdefects. These plastic foam liners are most often cut as a disk orannular “donut” from a sheet of material and then inserted or punchedinto the closure or bottle cap. The disk or “donut” is cut to a diameterlarger than an inside diameter of the closure locking bead of the capand this diametrical interference suffices to retain the liner in thecap during transport and application to the container or bottle withouthaving to resort to more expensive retention processing such as hot meltgluing.

[0014] A characteristic of the plastic foam liner systems is that theonly retention mechanism holding the liner within the cap is theabove-mentioned diametrical interference between the liner and theclosure locking bead of the cap. In this case, a certain amount of linershifting can occur for various reasons. Firstly, during mechanicalcutting and insertion processes, the liner might not be insertedperfectly axially with respect to the cap. Secondly, during applicationof the closure to a container neck, a certain amount of cap distortionand/or cocking, that is tilting or slanting, with respect to thecontainer neck may occur. In other words, a first portion of theperimeter of the closure may seat on the container neck prior to anotherportion circumferentially removed from the first portion. This “cocking”action can “pull” the liner in the direction of the first portion thusshifting the liner with respect to the container and the closure.Finally, the forces involved in the vertical application of the closureto a plastic container generally cause some axial compression of theplastic container, resulting in escape of some of the air in theheadspace above the liquid within the container. The flow of this airoutward through the neck of the container can cause the liner to shiftwith respect to both the container and the closure.

[0015] In the past, the diameter of the liners used has been sufficientto accommodate the above described shifting while still ensuring thatthe liner contacts the crown sealing surface of a conventionalblown-finish container around its full circumference. More recently,however, alternate manufacturing techniques have emerged which make itdesirable to increase the internal diameter of the container neck bore.Specifically, crown finishes of the container neck formed by injectionmolding or compression molding place a premium on increasing theinternal diameter of the bore in order to save material and reducemanufacturing cycles. In addition, increased bore diameters decrease thepossibility of damaging the top finish of the container neck fromincidental contact with fill tubes of container filling equipment.

[0016] Disadvantageously, increasing the bore diameter of a containerneck decreases the top “land” area of the crown finish. Across-sectional comparison of the land areas for a conventional blownfinish versus the more recent injected or compression finishes is shownin FIGS. 13 and 14. In FIGS. 13 and 14, the “land” surface or area ofthe two different types of finishes are indicated by L₁ and L₂,respectively.

[0017] It has now been observed that the above described liner shiftingmay be sufficient to cause the liner to miss the reduced land area L₂presented by bottles having increased bore size, as shown in FIG. 14,resulting in inadequate sealing and leakage.

[0018] What is needed is a cap which overcomes the above and otherdisadvantages of known caps.

SUMMARY OF THE INVENTION

[0019] An object of the present invention is to provide an improvedbottle cap which allows a user to remove the bottle cap from a containerin a facile manner.

[0020] Another object of the present invention is to provide an improvedbottle cap which allows only a single use thereof, thus preventingmisuse of a reusable bottle.

[0021] Another object of the present invention is to provide an improvedbottle cap having additional structure to minimize and/or preventexcessive shifting of a liner with respect to the bottle cap and thecontainer to which it is applied when the bottle cap is applied to thecontainer.

[0022] An object of the present invention is to provide an improvedbottle cap to minimize and/or prevent excessive liner shifting withoutthe need for costly retention processes such as hot melt gluing.

[0023] In summary, one aspect of the present invention is directed to abottle cap including a top, a skirt, a locking bead, a tear tab, and aline of weakness. The top has a perimeter. The skirt depends from theperimeter and has a bottom edge. The locking bead radially extendsinward from the skirt intermediate the top and the bottom edge. The teartab extends downward from the bottom edge. The line of weakness extendsalong the skirt upward from the bottom edge and onto the top.

[0024] The skirt may include a frustoconical upper portion and acylindrical lower portion in which the line of weakness extends from thebottom edge, though the cylindrical lower portion, through thefrustoconical upper portion and onto the top.

[0025] The cap may include a second line of weakness extending along theskirt upward from the bottom edge, through the cylindrical lower portionand terminating in the frustoconical upper portion.

[0026] Another aspect of the present invention is directed to a bottlecap including a top, a skirt, a locking bead, a tear tab, a line ofweakness, and a gusset. The top has a perimeter. The skirt depends fromthe perimeter and has a bottom edge. The locking bead radially extendsinward from the skirt intermediate the top and the bottom edge. The teartab extends downward from the bottom edge. The first line of weaknessextends along the skirt upward from the bottom edge. The gusset extendsfrom the locking bead into the skirt. The gusset may extend along aportion of the line of weakness.

[0027] The cap may include a second line of weakness and a secondgusset, the second line of weakness extending along the skirt upwardfrom the bottom edge terminating adjacent the perimeter, and the secondgusset extending from the locking bead into the skirt, the second gussetextending along a portion of the second line of weakness.

[0028] Another aspect of the present invention is directed to a bottlecap including a top having a perimeter, a skirt depending downward fromthe perimeter, the skirt having a bottom edge, a locking bead radiallyextending inward from an interior surface of the skirt intermediate thetop and the bottom edge, a tear tab extending downward from the bottomedge, a first line of weakness proximate the tear tab and extendingupward from the bottom edge and across the locking bead, and reinforcingstructure including a first gusset extending from the locking bead intothe skirt and along a portion of the first line of weakness to provideleverage for tearing through the locking bead.

[0029] Another aspect of the present invention is directed to a bottlecap including a top having a perimeter, a skirt depending downward fromthe perimeter, the skirt having a bottom edge, a locking bead radiallyextending inward from an interior surface of the skirt intermediate thetop and the bottom edge, and a sealing bead radially extending inwardfrom an interior surface of the skirt approximately midway between thetop and the locking bead. The cap may include a tear tab extendingdownward from the bottom edge, a first line of weakness proximate thetear tab and extending upward from the bottom edge and across thelocking bead.

[0030] Another aspect of the present invention is directed to a bottlecap including a top having a perimeter, a skirt depending downward fromthe perimeter, the skirt having a bottom edge, a tear tab extendingdownward from the bottom edge, first and second lines of weaknessproximate the tear tab and extending upward along the skirt from thebottom edge defining a tear tab portion between the lines of weakness,and gripping structure for facilitating gripping of the tear tab portionby a user as the tear tab portion is torn away from the skirt, theribbing located on the tear tab portion intermediate the bottom edge andthe top. The gripping structure may include ribs. The ribs may belocated on an internal surface of the skirt.

[0031] Another aspect of the present invention is directed to a bottlecap including a top, a skirt and a liner retaining protrusion. The tophas a perimeter and an inside surface. The skirt depends downwardly fromthe perimeter. The liner retaining protrusion depends downwardly fromthe inside surface of the top and is adapted to prevent shifting of aliner with respect to the cap. The top, skirt and liner retainingprotrusion may be monolithically formed. The liner retaining protrusionmay be conical. The liner retaining protrusion may also be spike-shaped.Alternatively, the liner retaining protrusion may include a cylindricalwall which depends downwardly from the inside surface of the top. Theliner retaining protrusion may include an outwardly extending beadextending from a lower portion of the cylindrical wall.

[0032] Yet another aspect of the present invention is directed to aclosure including a cap and a liner. The cap includes a top having aperimeter and an inside surface, a skirt depending downward from theperimeter, and a liner retaining protrusion depending downwardly fromthe inside surface of the top. The liner is positioned adjacent theinside surface of the cap within the skirt. The liner retainingprotrusion extends into the liner to retain the liner and prevent theliner from axially shifting with respect to the cap. The liner retainingprotrusion may extend into and through the liner. Alternatively, theliner retaining protrusion may extend through the liner such that anintermediate portion extends axially through the liner and an endportion extends below the liner, the end portion extending at an anglewith respect to the intermediate portion.

[0033] The accompanying drawings, which are incorporated in and form apart of this specification, illustrate embodiments of the invention and,together with the description, serve to explain the principles of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0034]FIG. 1 is a top perspective view of a bottle cap in accordancewith the present invention.

[0035]FIG. 2 is a sectional view of the cap shown in FIG. 1 takensubstantially along line 2-2 of FIG. 1.

[0036]FIG. 3 is an enlarged detailed view of an interior portion of thecap shown in FIG. 1.

[0037]FIG. 4 is a sectional view of the cap shown in FIG. 1 takensubstantially along line 4-4 of FIG. 1 positioned on a neck of acontainer.

[0038]FIG. 5 is a top perspective view of a modified bottle cap similarto that shown in FIG. 1 including a non-spill well in accordance withthe present invention.

[0039]FIG. 6 is a sectional view of the cap shown in FIG. 5 takensubstantially along line 6-6 of FIG. 5.

[0040]FIG. 7 is a top perspective view of a modified bottle cap similarto that shown in FIG. 1 in accordance with the present invention.

[0041]FIG. 8 is a top plan view of a portion of the cap shown in FIG. 7.

[0042]FIG. 9 is a top perspective view of a modified bottle cap similarto that shown in FIG. 5 including a non-spill well in accordance withthe present invention.

[0043]FIG. 10 is a top plan view of a modified cap similar to that shownin FIG. 1 in accordance with the present invention.

[0044]FIG. 11 is a sectional view of the cap shown in FIG. 10 takensubstantially along line 11-11 of FIG. 10.

[0045]FIG. 12 is a sectional view of a portion of the cap shown in FIG.10 taken substantially along line 12-12 of FIG. 10 schematically showingthe height of a seal bead relative to a container neck crown inaccordance with the present invention.

[0046]FIG. 13 is a schematic cross-sectional view of a container neckhaving a conventional blown finish.

[0047]FIG. 14 is a schematic cross-sectional view of another containerneck having a injected or compression finish.

[0048]FIG. 15 is a top plan view of a modified cap in accordance withthe present invention similar to that shown in FIG. 1 in accordance withthe present invention.

[0049]FIG. 16 is a sectional view of the cap shown in FIG. 16 takensubstantially along line 16-16 of FIG. 15.

[0050]FIG. 17 is a bottom plan view of the cap of FIG. 15.

[0051]FIG. 18 is a sectional view showing the cap of FIG. 16 incombination with a liner.

[0052]FIG. 19 is a sectional view showing the cap of FIG. 16 and theliner of FIG. 18 in combination with the container neck of FIG. 15.

[0053]FIG. 20 is a sectional view of a modified cap in accordance withthe present invention similar to that shown in FIG. 15.

[0054]FIG. 21 is a sectional view, similar to FIG. 16, illustrating amodified cap and liner in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] Reference will now be made in detail to the preferred embodimentsof the invention, examples of which are illustrated in the accompanyingdrawings. While the invention will be described in conjunction with thepreferred embodiments, it will be understood that they are not intendedto limit the invention to those embodiments. On the contrary, theinvention is intended to cover alternatives, modifications andequivalents, which may be included within the spirit and scope of theinvention as defined by the appended claims.

[0056] Turning now to the drawings, wherein like components aredesignated by like reference numerals throughout the various figures,attention is directed to FIGS. 1-4. A bottle cap 30 in accordance withthe present invention is intended for use with large water bottles, forexample, five gallon bottles of the type that are inverted and placed ina water dispenser. It will be understood, however, that the inventionmay be used with caps of other design. The bottle cap is formed ofplastic or other suitable materials. Preferably, low densitypolyethylene is used in the construction of the bottle cap in accordancewith the present invention, however, one should appreciate that othersuitable materials can be used. The material of the bottle cap, togetherwith the generally thin-walled construction of the cap, generallyprovide for a bottle cap which tightly conforms to a container neckcrown

[0057] Cap 30 has a top 31 and a skirt 32 which depends from a periphery35 of cap 30. In the illustrated embodiment, periphery 35 forms a labelpositioning bead within which a label or other indicia may be applied tothe cap. Skirt 32 extends downwardly terminating in a bottom edge 36.

[0058] An upper portion 39 of skirt 32 is frustoconically shaped havingan inward-upward slant. The upper slanted portion is relativelythin-walled and is not as rigid as conventional caps such as the onesdisclosed by U.S. Pat. No. 5,232,125 to Adams, the entire content ofwhich is incorporated herein by this reference. The thin-walledconfiguration allows the cap to conform to the crown finish 42 of abottle neck 43 as it is applied to the neck. The ability of upper skirtportion 39 to conform with crown 42 also increases the performance ofliners, such as the foam disk disclosed in U.S. Pat. No. 5,687,865 toAdams, the entire content of which is incorporated herein by thisreference. In particular, as upper skirt 39 conforms with the shape ofneck crown 42, the contact surface area between the liner and the neckcrown increases significantly.

[0059] One should appreciate that the upper portion of the skirt neednot be slanted but may instead be cylindrical. On an interior of skirt32 is an upper locking bead 40, which is located approximately at theintersection of slanted upper portion 39 and a cylindrical lower portion41 of the skirt. Locking bead 40 fits snugly below upper crown portion42 conventionally formed on the finish of a five gallon water bottleneck 43 as shown in FIG. 4.

[0060] Optionally, a non-ovality bead 44 may be provided in the form ofan outwardly and/or inwardly extending projection formed on the exterioradjacent bottom edge 36 of skirt 32 in order to preserve the round shapeof skirt 32 and also to rigidify lower edge 36. In the form of theinvention shown in FIGS. 1-4, there is an internal top seal bead 45adjacent the intersection of top 31 and slanted skirt portion 39 whichengages bottle neck crown 42 to inhibit leakage. An additional internalseal bead 46 is located on the interior of slanted portion 39intermediate top 31 and locking bead 40. As noted above, the thin-walledconfiguration of the upper slanted portion 39 allows cap 30 to conformto the crown finish 42 of a bottle neck 43 as it is applied to the neck.This configuration increases the effectiveness of side seal bead 46. Oneshould appreciate that a cap can be provided with either a top seal beador an internal seal bead, or both a top seal bead and an internal sealbead in accordance with the present invention.

[0061] In one embodiment of the present invention, seal bead 46 radiallyextends inwardly from an inner surface of slanted upper skirt portion 39intermediate a bottom surface of top 31 and locking bead 40. Seal bead46 has a minimum inside diameter which is slightly less than acorresponding outside diameter of crown 42 of neck 43. Preferably, sealbead 46 is located approximately midway between the bottom surface oftop 31 and locking bead 40, as is discussed in greater detail below.

[0062] A pair of spaced lines of weakness or tear lines 48, 49 extendupwardly from bottom edge 36. Tear line 48 extends upwardly from bottomedge 36, along skirt 32 and onto top 31 while tear line 49 terminatesapproximately at the top of skirt 32 adjacent periphery 35 of top 31. Asshown, tear lines 48 and 49 extend on the exterior of skirt 32, and tearline 48 continues on the interior of top 31. One should appreciate thatother configurations may be used. For example, it is possible to form aportion of the lines of weakness on the exterior of the top. Such aconfiguration would advantageously prevent any possibility ofmisalignment between line of weakness portions on the exterior of theskirt and top because, in the event that standing steel is used to formthe lines of weakness, the standing steel used to form both portions ofthe line of weakness would be located in the mold cavity.

[0063] It is likewise possible to form a portion of the lines ofweakness on an interior portion of the skirt. In the event that a lineof weakness is located on the interior of the skirt, the line ofweakness should not violate the sealing bead of the cap in order toprovide an effective fluid seal.

[0064] As noted above, a portion of tear line 48 continues onto top 31and has a curved portion 50 which extends radially inward along top 31to an arcuate portion and terminates adjacent to periphery 35 of top 31.In the embodiment shown in FIGS. 1-4, tear line 48 extends along top 31from a first point P₁ adjacent periphery 35 along curved portion 50 to asecond point P₂ adjacent periphery 35 and circumferentially spaced fromthe first point P₁. In this embodiment, first point P₁ and second pointP₂ are circumferentially spaced apart in the range of approximately 45°to 90°.

[0065] One should appreciate, however, that first point P₁ and secondpoint P₂ need only to be spaced apart a distance that is large enough toallow a sufficient portion of locking bead 40 to bend away from crown 42thus allowing removal of cap 30 from bottle 43 in a facile manner asdiscussed below. For example, first point P₁ may be spaced from secondpoint P₂ by approximately 20°, and are preferably spaced apart at leastapproximately 30-45°.

[0066] On the other hand, tear line 49 does not continue onto top 31 inthis embodiment. Instead, a stop 51 is provided on top 31 adjacentperiphery 35 to prevent splitting action along tear line 49 fromcontinuing onto top 31. Stop 51 is provided in the form of a thickenedmember projecting upwardly from top 31 adjacent periphery 35. Stop 51terminates tearing along line 49. One should appreciate that other formsof stop can be used in accordance with the present invention. Forexample, additional material may be provided adjacent the upper terminusof tear line 49 in order to prevent splitting action along tear line 49from propagating onto top 31. One should appreciate that the stop canalso be positioned slightly below the top on the slanted skirt portion,and/or positioned adjacent the locking bead in accordance with thepresent invention. One should also appreciate that line of weakness mayalso terminate at the locking bead in which case, the locking bead mayserve as the stop.

[0067] A tab 52 extends downwardly from bottom edge 36 of skirt 32between tear lines 48 and 49. Pulling tab 52 upward causes skirt 32 tosplit along tear lines 48 and 49 forming a tear tab portion 53 whichincludes a portion of skirt 32 between tear lines 48 and 49. The upwardpulling of tab 52 and tearing of tear tab portion 53 from the remainderof the skirt, in effect, interrupts the continuity of locking bead 40and enables the cap 30 to be pulled off the bottle neck with relativeease. The function of tab 52 and tear tab portion 53 is that whengripped by a consumer and pulled upward and/or outward it causes skirt32 to tear along tear lines 48 and 49 so that the function of bead 40 inretaining the cap on the bottle neck is overcome. Continued pulling oftab 52 removes cap 30 from bottle neck 43. To facilitate the consumergripping tab 52, a plurality of ribs 54 spaced upwardly from the bottomend of tab 52 are formed on the back surface of tab 52. One shouldappreciate one or more ribs may be provided for this purpose on eitherone or both of the external and internal surfaces of tear tab 52.

[0068] Another aspect of the present invention is concerned withstructure provided on the interior of skirt 32 adjacent the intersectionof tear lines 48 and 49 with upper locking bead 40. Circumferentiallyspaced reinforcing gussets 56 are provided which extend from a bottomportion of locking bead 40 downwardly at an angle into an adjacentportion of cylindrical lower portion 41 of skirt 32. Such gussets notonly provide structural integrity to locking bead 40 but also assist inapplying cap 30 to neck 43. In particular, the gussets also serve as aramp against crown 42 for facilitating bead 40 in passing over crown 42upon application of cap 30 to neck 43.

[0069] Additionally, tear line gussets 57 also extend from a bottomportion of locking bead 40 downwardly at an angle into an adjacentportion of cylindrical lower portion 41 of skirt 32 and are positionedimmediately adjacent tear lines 48 and 49. Tear line gussets 57 increaseleverage of tear tab portion 53 to facilitate tearing through lockingbead 40 as a consumer pulls tab 52 upwardly to split skirt 32 alonglines of weakness 48 and 49. In particular, tear line gussets 57, ineffect, form a pry bar which provides the leverage necessary to tearthrough locking bead 40 and also prevents tear tab portion 53 frombending excessively as tear tab 52 is pulled upwardly by the consumer.

[0070] Tear line gussets 57 may also minimize and/or eliminate thepossibility of tab 52 breaking off from cap 30 as a user pulls upwardlyon tab 52 and failing to split tear lines 49 and 48 through locking bead40. An additional tear tab gusset 58 can be provided between tear linegussets 57 to further reinforce the connection between tear tab 52 andlocking bead 40.

[0071] The illustrated gussets 56, 57 and 58 are substantiallytriangular shaped flat members extending from locking bead 40 into lowerportion 41 of skirt 32. One should appreciate that the gussets may havea variety of shapes, and other types of reinforcing structure can beused. For example, the gussets may be arcuate shaped, sweeping from thelocking bead into the lower portion of the skirt.

[0072] As shown in FIG. 2, tear line gussets 57 overlap external teartab ribs 59 which are provided on either side of tear tab 52, as shownin FIGS. 1 and 2. Tear tab ribs 59 extend substantially vertically alonglines of weakness 48 and 49. This configuration provides substantiallycontinuous reinforcing structure along the tear tab which providesstructural integrity to the tear tab. In particular, such reinforcingstructure directs the tear along lines of weakness 48 and 49 andminimizes the possibility of tearing action to propagate away from lines48 and 49. Furthermore, such continuous reinforcing structure increasesleverage applied by a user to tear tab 52 and tear tab portion 53thereby facilitating tearing through the continuous portion of lockingbead 40. One should appreciate, however, that other types ofsubstantially continuous reinforcing structure can be utilized inaccordance with the present invention. For example, internal and/orexternal tear tab ribs which extend into the locking bead can be used.Alternatively, the tear tab may include a continuous thickened portionwhich is thicker relative to the skirt. Such a continuous thickenedportion can extend from the lower edge of the skirt to the locking bead,to the upper angled portion of the skirt, and/or to the top.

[0073] A notch 60 is also provided in a bottom portion of locking bead40 opposite and in line with each line weakness 48 and 49, as shown inFIGS. 2 and 3. Notch 60 facilitates tearing action along the lines ofweakness through the locking bead without violating locking bead 40,that is, compromising the portion of the locking bead which engages acontainer. Although notch 60 is shown on an internal surface of the cap,one should appreciate that other variations can be utilized within thescope of the present invention. For example, a notch can be provided onan external surface of the skirt overlying the bottom portion of thelocking bead such that the notch facilitates tearing action along thelines of weakness without violating the locking bead.

[0074] In use, when cap 30 is applied to neck 43, it seats on the bottleneck and cannot be removed from the bottle so long as the tear lines 48and 49 are intact. To open the bottle, a consumer grips tab 52. Theoutward slanting of tab 52 away from bottle neck 43 facilitates grippingtab 52 whereby transverse ribs 54 improve the user's grip on the tab.The user then pulls vertically upwardly/outwardly on tab 52 and thuscauses tearing along tear lines 48 and 49 whereby tab 52 rolls back uponitself. Advantageously, the vertical motion is equally suited for use byboth right-handed and left-handed users. The rolling of the tab 52allows energy transformation into tear energy, thus making tearing ofthe tear lines 48 and 49 easier for the consumer. Tear line gussets 57control the bending stiffness of tear tab portion 53 along the length ofskirt 32 adjacent locking bead 40. This transforms pull force energyinto tear strain energy, reducing the force required to tear the skirtalong tear lines 48 and 49 and through locking bead 40.

[0075] As the user continues to pull tab 52 in substantially the samemotion, cap 30 continues to split along tear lines 48 and 49 to the topof upper inclined portion 39. At this point, splitting action along tearline 48 continues onto top 31. However, stop 51 prevents the splittingaction along tear line 49 from propagating onto top 31.

[0076] As the user yet continues to pull tab 52 in substantially thesame motion, cap 30 continues to split along tear line 48, specificallythrough first point P₁ and along curved portion 50 thereby splitting top31. As a result of this motion, the user simultaneously pulls a portionof locking bead 40 away from crown 42 of bottle 43. As the splittingaction along curved portion 50 of tear line 49 nears second point P₂, asufficient portion of locking bead 40 is pulled away from crown 42 whichallows the user to remove cap 30 from bottle 43 in a facile manner. Inparticular, the user need not additionally grasp lower portion 41 ofskirt 32 and pry the cap away from the bottle, although this alternateprocess of removal has been judged acceptable.

[0077] Because locking bead 40 is substantially destroyed upon removalby a consumer, cap 30 may only be used once. This configuration isadvantageous when used in combination with returnable bottles becausesuch configuration prevents misuse of the returnable bottle. Forexample, since the locking bead is inoperable once a user tears the teartab portion through the locking bead, a user cannot reuse the cap toreseal the container. Advantageously, this configuration discouragesmisuse of returnable bottles and, in particular, discourages the reuseof returnable bottles to store possibly harmful and dangeroussubstances.

[0078] Many features of the present invention provide for a bottle capwhich is lightweight. For example, the gussets allow for thinner wallsof the skirt and top. The lighter weight advantageously results in lessdistortion of caps located in the bottom of shipping boxes due tosettling during shipping and handling. Furthermore, the light-weightdesign provides for a less-expensive and environmentally-friendly capbecause less material is used to manufacture the cap.

[0079] Advantageously, the structural walls of the cap of the presentinvention are more uniform in design, a feature which reducesenvironmental stress cracking. Since the bottle caps used to seal largewater bottles generally are always under stress when seated on acontainer neck of a bottle. Environmental stress cracking may be causedby great variations in thickness of a low density polyethylene closureunder stress. Such environmental stress cracking often results fromexcessive wall thickness. The bottle cap of the present invention is ofa thin-walled design which avoids excessive wall thicknesses found inprior caps. Accordingly, the thin-walled design of the bottle cap of thepresent invention minimizes and/or prevents environmental stresscracking commonly found in prior caps.

[0080] Turning now to FIGS. 5 and 6, a cap 30 a is of the “non-spillvariety”. In many respects, the structure of cap 30 a resembles that ofcap 30 discussed above. Cap 30 a includes a central vertical well 62. Aninternal bead 63 is formed at the bottom of well 62. The purpose andfunction of well 62 will be understood by reference to U.S. Pat. No.5,370,270 to Adams et al., the entire contents of which is incorporatedherein by this reference.

[0081] Cap 30 a also includes tear lines 48 a and 49 a similar to thosediscussed above. The portion of tear line 49 a which extends along top31 a, however, includes linear portions as well as a curved portion. Inparticular, tear line 48 a includes a first straight portion 66, whichextends radially inward from a first point adjacent periphery 35 a, anarcuate portion 67, and a second linear portion which extends radiallyoutward and terminates at a second point adjacent periphery 35 a spacedfrom the first point. As illustrated, portions 66, 67 and 68 are formedon an exterior surface of cap 30 a in this embodiment.

[0082] One should appreciate that the portion of tear line 48 a whichextends along the top can have a wide variety of configurations. Forexample, the top portion of the tear line can include an intermediatelinear portion interconnecting first and second linear portions 66 and68 instead of arcuate portion 67. Such a straight portion can besubstantially tangential to well 62 or can be spaced outwardly from well62. Furthermore, a single linear portion, or chord portion, can be usedinstead of portions 66, 67 and 68.

[0083] The use and operation of removing cap 30 a from a bottle issimilar to that of cap 30 discussed above. In particular, a user maygrip tab 52 a and pull the tab to split cap 30 a along tear lines 48 aand 49 a, bend locking bead 40 a away from a bottle, and remove cap 30 afrom the bottle, all in a facile manner.

[0084] In one embodiment of the present invention, shown in FIGS. 7 and8, a cap 30 b has a top 31 b, here shown as a substantially flat disc,and having a peripheral depending skirt 32 b. Skirt 32 b includes anoutward-downward slanted upper skirt portion 39 b. Below upper skirtportion 39 b is a substantially cylindrical lower skirt portion 41 b. Onthe interior of lower skirt portion 41 b is an internal locking bead 40b which engages under a bead on the exterior of a container neck. Cap 31b includes a locking bead which extends around the circumference oflower skirt portion in the same manner as locking bead 40 describedabove.

[0085] Lines of weakness or tear lines 48 b and 49 b extend upwardlyalong skirt 32 b. A pull tab 52 b extends downwardly from lower skirtportion 41 b between tear lines 48 b and 49 b. Tear line 48 b extendsupwardly and onto top 31 b and includes a straight portion 71 whichextends across top 31 b. Tear line 49 b terminates adjacent theperiphery of top 31 b. A stop 51 b is provided to prevent splittingaction along tear line 49 b from propagating onto top 31 b. Stop 51 b isprovided in the form of additional material which forms a thickenedportion of top 31 b adjacent the upper terminus of tear line 49 b.

[0086] As shown in FIG. 8, straight portion 71 is slightly offset fromtear line 48 b toward stop 51 b in accordance with the presentinvention. In particular, straight portion 71 is offset slightly to theleft as viewed in FIG. 8. Such configuration minimizes and/or preventsany tendency of splitting action along tear line 48 b to propagate awayfrom straight portion 71. For example, offsetting straight portion 71slightly to the left minimizes or prevents splitting action along tearline 48 b from propagating to the right (as shown in FIG. 8) alongperipheral bead 35 b. Furthermore, the offset configuration may beadvantageous from an alignment standpoint. As the alignment tolerancesbetween a mold core and a mold cavity used to manufacture cap 30 mayvary, the mold can be configured such that any variation in alignmentwill result in an offset to the left, varying only in degree as to howmuch it is offset to the left.

[0087] In use and operation, removing cap 30 b from a bottle is similarto that of the above caps. In particular, a user may grip tab 52 b andpull the tab to split cap 30 b along tear lines 48 b and 49 b, bendlocking bead 40 b away from a bottle, and remove cap 30 b from thebottle, all in a facile manner.

[0088] In one embodiment of the present invention, shown in FIG. 9, acap 30 c has a top 31 c having a non-spill well 62 c and a peripheraldepending skirt 32 c. Skirt 32 c includes an outward-downward slantedupper skirt portion 39 c. Below upper skirt portion 39 c is asubstantially cylindrical lower skirt portion 41 c. On the interior oflower skirt portion 41 c is an internal locking bead 40 c which engagesunder a bead on the exterior of a container neck. Cap 30 c includes alocking bead which extends around the circumference of the lower skirtportion in the same manner as locking bead 40 described above.

[0089] Lines of weakness or tear lines 48 c and 49 c extend upwardlyalong skirt 32 c. A pull tab 52 c extends downwardly from lower skirtportion 41 c between tear lines 48 c and 49 c. Tear line 48 c extendsupwardly along skirt 32 c and onto top 31 c and includes a straightportion 75 which extends radially inward from perimeter 35 c across aportion of top 31 c and diverges outwardly from well 62 c. Tear line 49c similarly extends upwardly and onto top 31 c and includes a straightportion 76 which extends radially inward from perimeter 35 c anddiverges outwardly from well away from straight portion 75.

[0090] In use and operation, removing cap 30 c from a bottle is similarto that of the above caps. In particular, a user may grip tab 52 c andpull the tab to split cap 30 c along tear lines 48 c and 49 c, bendlocking bead 40 c away from a bottle, and remove cap 30 c from thebottle, all in a facile manner.

[0091] In one embodiment of the present invention, shown in FIGS. 10-12,a cap 30 d has a top 31 d and a peripherally depending skirt 32 d. Skirt32 d includes an outward-downward slanted upper skirt portion 39 d.Below upper skirt portion 39 d is a substantially cylindrical lowerskirt portion 41 d. On the interior of lower skirt portion 41 d is aninternal locking bead 40 d which engages under a bead on the exterior ofa container neck. As shown, locking bead 40 d extends around thecircumference of lower skirt portion 41 d.

[0092] Lines of weakness or tear lines 48 d and 49 d extend upwardlyalong skirt 32 d. A pull tab 52 d extends downwardly from lower skirtportion 41 d between tear lines 48 d and 49 d. Tear line 48 d extendsupwardly and onto top 31 d and includes a straight portion 71 d whichextends across top 31 d. Tear line 49 d terminates adjacent theperiphery of top 31 d. A rectangular stop 51 d is provided to preventsplitting action along tear line 49 d from propagating onto top 31 d.Stop 51 d is provided in the form of additional material which forms athickened portion of top 31 d adjacent the upper terminus of tear line49 d.

[0093] As shown in FIG. 10, tear lines 48 c and 49 c extend through anupper portion of periphery 35 d to facilitate tearing action along thetear lines and through the additional material of periphery 35 d.

[0094] Also shown in FIG. 11, internal ribbing 78 is provided on aninternal surface of tear tab portion 53 d for facilitating gripping oftear tab portion 53 d by a user as it is pulled away from the remainderof skirt 32 d. Ribbing 78 is located on tear tab portion 53 dintermediate bottom edge 36 d and top 31 d, and more particularlybetween bottom edge 36 d and locking bead 40 d. The ribbing illustratedin FIG. 11 includes horizontally extending ribs 78 on an internalsurface of skirt 32 d, however, one should appreciate that other formsof ribbing can be utilized in accordance with the present invention. Forexample, circular protrusions can be provided instead of, or in additionto, the illustrated horizontal ribs. One should also appreciate thatsuch ribbing can be provided on either an internal or an externalsurface of the skirt provided the shape facilitates gripping by a user.

[0095] Also shown in FIG. 11, seal bead 46 d radially extends inwardlyfrom an inner surface of slanted upper skirt portion 39 d intermediate abottom surface of top 31 d and locking bead 40 d. Seal bead 46 d has aminimum inside diameter which is slightly less than a correspondingoutside diameter of crown 42 of neck 43 (not shown in FIG. 11), whichdiameter is generally standardized within the industry. Preferably, sealbead 46 d is located approximately midway between the bottom surface oftop 31 d and locking bead 40 d. In such configuration, the minimuminside diameter of seal bead 46 d is slightly less than the maximumoutside diameter of crown 42 and is thus adapted to sealingly engagecrown 42 when the cap is applied to the container. As seal bead 46 d islocated approximately midway between the top and locking bead, seal bead46 d will engage crown 42 proximate the maximum diameter of crown 42thus providing an improved fluid seal, in part, because sealing forcesof seal bead 46 d upon crown 46 d extend in a substantially radialdirection.

[0096] Because seal bead 46 d is located approximately midway betweenthe bottom surface of top 31 d, locking bead 40 d extends substantiallyalong an imaginary plane P which extends through the maximum outerdiameter of crown 42, as is schematically shown in FIG. 12. One shouldappreciate that the position of cap 30 d relative to crown 42 shown inFIG. 12 is schematic in nature, and that thin-walled cap 30 d isactually dimensioned to stretch over crown 42 in such a manner that topseal bead 45 d, lower seal bead 46 d and locking bead 40 d would eachcontact and compress against a respective portion of crown 42. Inparticular, the inside diameters of top seal bead 45 d, lower seal bead46 d and locking bead 40 d are all less than the maximum outsidediameter of crown 42. Accordingly, upon application by pushing cap 30 don container neck 43, upper portion 39 d and lower portion 41 d of skirt32 d stretch a sufficient amount to allow locking bead 40 d to pass overcrown 42. The resulting tension in the walls of upper portion 39 d andlower portion 41 d cause each of upper seal bead 45 d lower seal bead 46d and locking bead 40 d to compress against respective portion of crown42.

[0097] As shown in FIG. 12, crown 42 has a radius of curvature R whereinplane P passes through the center C of the radius of curvature.Preferably, seal bead 46 d extends toward and sealingly engages crown 42within an angle θ of plane P. Angle θ is no greater than approximately30°, preferably in the range of 0° to 10°, and most preferably in therange of 0° to 5°. Such configuration allows an effective fluid sealdespite minor variations in the height of the crown common due totrimming of the container neck and other methods of finishing the neck.

[0098] Also shown in FIG. 12, locking bead 40 d includes notch 60 d forfacilitating tearing action along a line of weakness through the lockingbead. In this embodiment, notch 60 d extends into a bottom surface oflocking bead 40 d upwardly past the minimum inside diameter of thelocking bead and under an upper surface of the locking bead. Suchconfiguration allows the removal of a substantial amount of materialfrom the locking bead along the lines of weakness without violating theupper surface of the locking bead. The upper surface of the locking beadmay or may not be used as a secondary or supplemental fluid sealingsurface, that is supplemental to one or both of seal beads 45 d and 46d. In the event that the upper surface is utilized as a sealing surface,notch 60 d advantageously does not violate the upper surface and thusdoes not affect the ability of the upper surface to serve as asupplemental fluid seal.

[0099] In use and operation, removing cap 30 d from a bottle is similarto that of the above caps. In particular, a user may grip tab 52 d andpull the tab to split cap 30 d along tear lines 48 d and 49 d, bendlocking bead 40 d away from a bottle, and remove cap 30 d from thebottle, all in a facile manner. In the event a user releases tab 52 dand attempts to grip tear tab portion 53 d as the user attempts to tearthrough locking bead 40 d, ribbing 78 provides a gripping surface whichthe user can firmly grip and continuing tearing to remove cap 30 d froma bottle.

[0100] As noted above, increasing the bore diameter of a container neckdisadvantageously decreases the top “land” area of the crown finish. Across-sectional comparison of the land areas for a conventional blownfinish of container neck 43 versus the more recent injected orcompression finishes of container neck 80 is shown in FIGS. 13 and 14.In FIGS. 13 and 14, the “land” surface or area of the two differenttypes of finishes are indicated by L₁ and L₂, respectively.

[0101] In one embodiment of the present invention, in which cap 30 e isused in combination with a liner, for example, a foam liner 83, cap 30 eincludes a liner retainer in the form of three liner retainingprotrusions 84 which extend downwardly from an inside surface of top 31e, as shown in FIGS. 15-19. Liner retaining protrusions 84 prevent liner83 from shifting and missing the land area, and in particular, thereduced land area L₂ presented by bottles having an increased bore sizecontainer neck 80, as shown in FIG. 14, and thus prevent inadequatesealing and minimize or prevent leakage.

[0102] In many respects, the structure of cap 30 e resembles that ofcaps 30 and 30 a-d discussed above. Cap 30 e includes a top 31 e havinga perimeter 34 e and a skirt 32 e depending downward from perimeter 35e. Cap 30 e further includes tear lines 48 e and 49 e similar to thosediscussed above. A curved portion 50 e of tear line 49 e extends along abottom surface of top 31 e. Curved portion 50 e extends radially inwardfrom a first point adjacent periphery 35 e along an arcuate path whichalso extends radially outward and terminates at a second point adjacentperiphery 35 e spaced from the first point. In this embodiment, incontrast to prior embodiments, stop 51 e has a semicircular shape.

[0103] As illustrated in FIGS. 15-17, each liner retaining protrusion 84is in the form of a spike which extends downward from an inside surfaceof top 31 e. One should appreciate, however, that the actual shape andconfiguration of the liner retaining protrusion is subject toconsiderable variation. For example, the ends of each liner retainingprotrusion may include a barb or a spur to promote retention of or evenengagement with a liner.

[0104] Although the illustrated embodiment includes three linerretaining protrusions 84, one should appreciate that the actual numberis subject to considerable variation depending on closure and bottlefinish design. For example, one should appreciate that one or more linerretaining protrusions can be utilized in accordance with the presentinvention.

[0105] Turning now to FIG. 18, the height of liner retention protrusion84 is approximately the same as the thickness of the intended liner,that is, approximately the same as liner 83, as shown in FIGS. 18 and19. Normally, this height will be from approximately 0.050 inch to about0.25 inch. When a liner is punched into, or otherwise applied to aclosure, the liner retaining protrusions penetrate the foam liner andanchor it in position with respect to the closure. For example, as liner83 is applied to cap 30 e, spikes 84 penetrate foam liner 83 and anchorliner 83 in position with respect to cap 30 e, as shown in FIG. 18,thereby increasing foam retention and greatly reducing any tendency ofthe liner to shift from its axial positioning.

[0106] As schematically shown in FIG. 19, foam liner 83 compressesbetween crown 81 and the inside surface of top 31 e as cap 30 e isapplied to container neck 80. As liner retaining protrusions 84 preventliner 83 from shifting as cap 30 e is applied to container neck 80,liner 83 sufficiently contacts reduced land area L₂ to ensure adequatesealing and to minimize and/or prevent leakage.

[0107] The use and operation of removing cap 30 e from a bottle issimilar to that of caps 30 and 30 a-d discussed above. In particular, auser may grip tab 52 e and pull the tab to split cap 30 e along tearlines 48 e and 49 e, bend locking bead 40 e away from a bottle, andremove cap 30 e from the bottle, all in a facile manner. Advantageously,liner retaining protrusions 84 may also serve to better retain liner 83against the internal surface of top 31 e even as cap 30 e is removedfrom container neck 80.

[0108] One should appreciate that liner retaining protrusions can beutilized with all of the previously disclosed embodiments in accordancewith the present invention whenever a liner is used. One should furtherappreciate that liner retaining protrusions can also be used on avariety of other closures in accordance with the present invention. Forexample, FIG. 20 discloses a cap 30 f which has a general configurationwhich is similar to the closure disclosed by the Adams '125 patent. Inparticular, cap 30 f includes a top 31 f having a perimeter 35 f and askirt 32 f depending downward from perimeter 34 f. As illustrated inFIG. 20, liner retention projections 84 f are also provided to prevent aliner from shifting in the same manner as discussed above.

[0109] In one embodiment shown in FIG. 21, cap 30 g includes a linerretention protrusion in the form of a short hollow protrusion in theform of a cylindrical projection 89 which extends downwardly from aninside surface of top 31 g, as shown in FIG. 21. Cap 30 g isparticularly suited for use with donut-shaped liners of the typecommonly used with non-spill caps, such as the one disclosed by theAdams '125 patent. In particular, cylindrical projection 89 prevents adonut-shaped liner 92 from shifting and missing the reduced land area L₂presented by bottles having an increased bore size container neck 80, asshown in FIG. 14, thereby promoting adequate sealing. Preferably,cylindrical projection 89 includes a substantially vertical wall 90having an outside diameter approximately the same that of theconventional non-spill wells disclosed by the Adams '125 patent.However, the height of cylindrical projection 89 is substantiallyshorter than the height of a conventional non-spill well. For example,the height of cylindrical projection is approximately one-eighth tothree-eighths of an inch. One should appreciate, however, that wall 91need not be vertical and may instead have a slightly frustoconicalshape.

[0110] As illustrated in the embodiment shown in FIG. 21, cylindricalprojection 89 includes a radially outwardly extending bead 93. Bead 93extends radially outwardly from a bottom portion of cylindricalprojection 89 and serves to better retain liner 92 on cap 30 g in thatit provides additional interference between liner 92 and cap 30 g. Theuse and operation of removing cap 30 g from a bottle is similar to thatof caps 30 and 30 a-f discussed above.

[0111] Although the embodiment illustrated in FIG. 21 disclosescylindrical projection 89 in combination with spikes 83 g, one shouldappreciate that cylindrical projection 89 can be utilized alone, withoutspikes 83 g, in accordance with the present invention to retain theliner within the cap.

[0112] One should also appreciate that, in the event that spikes areused, either alone or in combination with a cylindrical projection orother liner retainer, the spikes may be dimensioned such that the tipsthereof are bent as a plastic foam liner is inserted or punched into theclosure or bottle cap. In particular, as shown in FIG. 21, the height ofspikes 83 g is substantially greater than the thickness of liner 92.Each end 96 of spikes 83 g are bent by the tooling which is used tomechanically insert liner 92 into cap 30 g. In particular, as liner 92is inserted into cap 30 g, spikes 83 g pierce one side of foam liner 92and extend through liner 92. As spikes 83 g extend out the other side offoam liner 92, ends 96 contact the insertion tooling and are bent to oneside, thus providing a hooked structure to further retain liner 92within cap 30 g.

[0113] In many respects the modifications of the various figuresresemble those of preceding modifications and the same referencenumerals followed by subscripts a, b, c and d designate correspondingparts.

[0114] For convenience in explanation and accurate definition in theappended claims, the terms “up” or “upper”, “down” or “lower”, “inside”and “outside” are used to describe features of the present inventionwith reference to the positions of such features as displayed in thefigures.

[0115] The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteaching. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application,to thereby enable others skilled in the art to best utilize theinvention and various embodiments with various modifications as aresuited to the particular use contemplated. It is intended that the scopeof the invention be defined by the claims appended hereto and theirequivalents.

What is claimed is:
 1. A bottle cap comprising: a top having a perimeterand an inside surface; a skirt depending downward from said perimeter;and a liner retaining protrusion depending downwardly from said insidesurface of said top adapted to prevent shifting of a liner with respectto said cap.
 2. A cap according to claim 1 wherein said top, skirt andliner retaining protrusion are monolithically formed.
 3. A cap accordingto claim 1 wherein said liner retaining protrusion is conical.
 4. A capaccording to claim 1 wherein said liner retaining protrusion has aheight of approximately 0.125 to 0.25 inches.
 5. A cap according toclaim 1 wherein said cap comprises two or more liner retainingprotrusions.
 6. A cap according to claim 1 wherein said liner retainingprotrusion is spike-shaped.
 7. A cap according to claim 1 wherein saidliner retaining protrusion comprises a cylindrical wall dependingdownwardly from said inside surface of said top.
 8. A cap according toclaim 1 wherein said liner retaining protrusion further comprises anoutwardly extending bead extending from a lower portion of saidcylindrical wall.
 9. A cap according to claim 1 wherein said skirtincludes a bottom edge, said cap further comprising: a locking beadradially extending inward from an interior of said skirt intermediatesaid top and said bottom edge; a tear tab extending downward from saidbottom edge; and a first line of weakness proximate said tear tab andextending upward along said skirt from said bottom edge and through saidlocking bead.
 10. A cap according to claim 1 further comprising asealing bead radially extending inward from an interior surface of saidskirt approximately midway between said top and said locking bead.
 11. Acap according to claim 1 wherein said skirt includes a bottom edge, saidcap further comprising: gripping structure for facilitating gripping ofsaid tear tab portion by a user as the tear tab portion is torn awayfrom said skirt, said ribbing located on said tear tab portionintermediate said bottom edge and said top.
 12. A closure comprising: acap including a top having a perimeter and an inside surface, a skirtdepending downward from said perimeter, and a liner retaining protrusiondepending downwardly from said inside surface of said top; and a lineradjacent said inside surface of said cap within said skirt; wherein saidliner retaining protrusion extends into said liner to retain said linerand prevent said liner from axially shifting with respect to said cap.13. A closure according to claim 12 wherein said liner retainingprotrusion extends into and through said liner.
 14. A closure accordingto claim 13 wherein said liner retaining protrusion extends through saidliner such that an intermediate portion extends axially through saidliner and an end portion extends below said liner, said end portionextending at an angle with respect to said intermediate portion.
 15. Aclosure according to claim 12 wherein said skirt includes a bottom edge,said closure further comprising: a locking bead radially extendinginward from an interior of said skirt intermediate said top and saidbottom edge; a tear tab extending downward from said bottom edge; and afirst line of weakness proximate said tear tab and extending upwardalong said skirt from said bottom edge and through said locking bead.16. A closure according to claim 12 further comprising a sealing beadradially extending inward from an interior surface of said skirtapproximately midway between said top and said locking bead.
 17. Aclosure according to claim 12 wherein said skirt includes a bottom edge,said closure further comprising: gripping structure for facilitatinggripping of said tear tab portion by a user as the tear tab portion istorn away from said skirt, said ribbing located on said tear tab portionintermediate said bottom edge and said top.